1- Field of the Invention
The present invention relates, generally speaking, to a camera designed for taking stereoscopic or three dimensional photographs with one of three stereoscopic bases, through two lenses respectively out of four fastened to the camera.
2- Description of the Prior Art
More especially the present invention relates to stereoscopic photography camera comprising a photosensitive medium to be exposed by two juxtaposed images arranged symmetrically about a symmetry plane perpendicular to the medium, two first rectilinear optical paths perpendicular to the medium, passing through centers of the images and spaced from a small stereoscopic base, two second optical paths symmetrical to the symmetry plane and including two first optical sections perpendicular to the medium and spaced from a large stereoscopic base, two first lenses centered on the first optical paths, and two lenses located on the second optical paths, the images being substantially located in an image focal plane common to the first and second lenses.
Such a camera having stationnary lens mounts, in which the second lenses have optical axes colinear with the first optical sections respectively, the second optical paths being wholly rectilinear and perpendicular to the photosensitive medium, is known under the name of NIMSLO 3D. This camera can record three stereograms taken respectively with three constant stereoscopic bases. A first stereogram is taken with a small base of 18 mm equal to the distance between the first optical paths and is composed of first images photographed through the first lenses. A second stereogram is taken with a mean base of 2.times.18=36 mm equal to the distance between one of the first optical paths and one of the second optical paths, on either side of the symmetry plane of the camera, and consists of two second images photographed with the corresponding first and second lenses between which a medium surface on which no image is produced, corresponds to the emplacement of one of the first images. A third stereogram is taken with a large base of 3.times.18=54 mm equal to the distance between the first optical sections or the second optical paths and consists of two third images photographed through the second lenses.
Whatever the stereogram selected, it appears that the stereogram is contained in a photosensitive medium area having a width equal to double that of the standard format of a 24.times.36 mm.sup.2 slide. Thus with a photographic film or 36 slides, only 18 stereogram can be produced with the NIMSLO 3D camera.
Moreover, to transpose the stereograms taken with the mean or large base into a standard slide frame in view of projecting the stereograms with a standard slide projector, a special printer must be used which still further increases the film developing costs. Stereograms printed from an original test print often result in a loss of quality, such as sharpness and color reproduction.